To two days, waiting for the craft to surface for air. Then it was an easy target. Other vessels manoeuvred themselves around the precious convoy ships to fill the gap left by the lingering vessel for fear that another U-boat would make merry in the unexpected opening.
In the British armoury, too, was the increasing ability of the decoders to pinpoint the position of U-boats. At the start of the war, the translation of the messages sent between the German admiralty and its ships was slow and provided only retrospective information. With practice, the ‘tapping’ system speeded up, providing accurate and detailed assistance for convoys and British ships on the whereabouts of the enemy. While the German commanders suspected a breach in security, they never identified where the leak was.
So 1941 proved to be a key year for the Allies in their fight against the U-boats. Although 432 ships were
Above: A US destroyer pulls alongside HMS Norfolk to refuel mid-voyage.
Sunk, the total was down on the previous year. The U-boat arm lost 35 of its craft.
When the U-boats turned their attentions to the pickings off America in early 1942, the pressure on the Atlantic convoys eased. But when the U-boats returned to Atlantic waters, it was with a vengeance.
At last U-boat manufacture was coming up to the levels hoped for by Donitz. Every month, 20 new U-boats left the ship yards.
World History
